Fisheye/Wide-Angle lens Calibration in OpenCV

Question

I know the default OpenCV Calibration systems model a Pinhole camera, but I\'m working with a system using extremely wide FOV lens (187-degrees). If there any existing way to d

Answer 1

OpenCV fisheye camera calibration module uses a method based on pin-hole camera model. In this model we have an angle between an optical axis of camera and ray of light from some object in front of camera. We also have an angle between optical axis and direction to point on undistorted image (corresponding to object). If calibration was performed correctly, these 2 angles will be equal. It means that if FOV of your camera is about 180 degrees, the distanse from center of undistorted image to edge of undistorted image will be equal to infinity. As a result OpenCV fisheye correction module (cv::fisheye) undistorts only a central part of image. More detailed explanation of this limitation I placed HERE.In my own results I got 140-150 degrees FOV in undistorted image. If FOV about 140-150 degrees is suitable for you, you can use cv::fisheye without any modification